A highly saturated (see fats and oils), solidified coconut oil (see coconut). Copha is extremely popular in Australia for everything from candy to pastries to toppings for cakes and cookies. It's typically melted with other ingredients (like chocolate), then drizzled over cake, or added to a candy mixture, and so on. Lard or shortening can be substituted for copha in recipes but won't impart that subtle coconut flavor.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.